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Friday, 5 January 2018

Meltdown and Spectre- The newest vulnerabilities-what you need to know.



There seems to be a lot of confusion regarding these new vulnerabilities, and as a IT security professional, I would like to take the time to review them .

There are two new vulnerabilities (actually three, but two are very closely related.) Meltdown and Spectre. Both vulnerabilities are hardware based within the actual CPU. This makes patching very difficult.

Meltdown
Meltdown is by far the most severe. With Meltdown an attacker can copy most if not all physical memory. This includes privileged memory in the kernel. The result of this is being able to steal passwords, session keys and other confidential material.

Patches are available to protect against this threat for most operating systems, however this does come at a cost.

Since the Operating System can no longer trust the CPU to do its job, the Operating System must step in to do it. This brings a performance penalty which has been described as ‘non-negligible’. Reports have put this figure as low as 10 per cent, while other reports put this figure at as high as 50 per cent. Any way you look at it your computer is going to be slower after applying the update.

As of this day on January 5, 2018, the only CPUs affected are the ones by Intel. While exploitation of Meltdown is theoretically possible with both AMD and ARM CPUs, researchers have noted no practical exploit has been achieved to date. However this may change at a later date. One notable exception is Apple and the new iPhone. It is vulnerable to the Meltdown attack. It seems Apple hired some ex-Intel designers to build their new ARM CPU.

Spectre
The second-Spectre is a very dangerous exploit. However, unlike Meltdown Spectre can only read memory from its own process-that is memory that it ‘owns’. It cannot read any privileged memory. Where this vulnerability could be exploited is with web browsers. One tab could be compromised with the Spectre vulnerability and be accessing privileged information in another tab.
Right now, there is no patch available for this vulnerability, and to make matters worse there is a JavaScript proof of concept floating around the Internet. It is just a matter of time before we see actual exploits in the wild.

There is a second variant of Spectre that can access all memory including privileged memory. Fortunately this vulnerability is considered to be far to difficult to use effectively.

Mitigation
To greatly reduce the chances of becoming a victim,  

  1. Make sure your anti-virus is up to date.  
  2. Ensure your computer is up to date with the latest software patches and updates. 
  3. Ensure all firewalls are turned on and functional.
  4. Make sure that your browser is running an ad blocker. Since Spectre is likely to spread via JavaScript, a very likely attack vector will be those ads since a lot of them utilize JavaScript (this has happened before with the Washington Post and New York Times among many others)



 On a side note, applying these patches on Windows may not be successful if you are running third party antivirus products. There are other reports that applying these patches will cause the infamous Blue Screen of Death (BSoD)

 Am I affected?

More than likely, yes. If you are running Microsoft Windows, Microsoft has a support web page at

Unfortunately, this site is geared more to IT professionals and the tools provided may be beyond the scope of some people.

For those who are looking for more technical explanation of these vulnerabilities check out Jake Williams (@MalwareJake) outstanding video at  https://www.youtube.com/watch?v=8FFSQwrLsfE

If you have any other questions, you should speak to a IT professional for advice. I can be contacted on Twitter @TheTeeStar

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